Question

我尝试通过滚动（通过单击按钮）进行分页。但是当我想为这个行动添加一些延迟时，等待新的承诺＆＃39; node在运行时给出错误如何从节点运行时转义此错误，这是代码片段，

 let scrapedData = yield nightmare
    .goto(nextExists)
    .wait(3000)
    .evaluate(function () {

      var links = [];
      var productList = "";
      var flag = true;

      while (flag) {
        var element = document.querySelectorAll('.load-more');
        console.log('aa ' + element[0].style.display == "");
        if (element[0].style.display == "") {
          element[0].click()
        } else {
          flag = false
        }
        await new Promise(resolve => setTimeout(resolve, 3000)); // error
        /*
        await new Promise(resolve => setTimeout(resolve, 3000));
                      ^^^
        SyntaxError: Unexpected token new
            at createScript (vm.js:80:10)
            at Object.runInThisContext (vm.js:139:10)
            at Module._compile (module.js:599:28)
            at Object.Module._extensions..js (module.js:646:10)
            at Module.load (module.js:554:32)
            at tryModuleLoad (module.js:497:12)
            at Function.Module._load (module.js:489:3)
            at Function.Module.runMain (module.js:676:10)
            at startup (bootstrap_node.js:187:16)
            at bootstrap_node.js:608:3
        */
      }
      console.log('all done')
})

Answer 1

您在async {。}}错过.evaluate(async function {})个关键字。

以下是您要实现的目标的最小示例：

const Nightmare = require('Nightmare');
const nightmare = new Nightmare({show: true});

const scrapedData = nightmare
    .goto('http://google.com')
    // You can use `await` keyword only in `async` functions
    // Async function *always* returns a promise which nightmare knows how to handle
    .evaluate(async function () {
        await new Promise(resolve => setTimeout(resolve, 3000));
    })
    .end()
    .then(() => console.log('All done'));

您可以阅读有关async/await here的更多信息。

nightmare.js，on .evaluate这给了我一个节点错误

1 个答案: